#include <REGX52.H>
#include "Delay.h"

unsigned char Key()
{
	unsigned char KeyNumber = 0;
	if(P3_1==0){Delay(20);while(P3_1==0);Delay(20);KeyNumber = 1;}
	if(P3_0==0){Delay(20);while(P3_0==0);Delay(20);KeyNumber = 2;}
	if(P3_2==0){Delay(20);while(P3_2==0);Delay(20);KeyNumber = 3;}
	if(P3_3==0){Delay(20);while(P3_3==0);Delay(20);KeyNumber = 4;}
	return KeyNumber;
}
